Reports from conservationists indicate that there has been a surge in poachers using poison arrows and spears to kill elephants in southern Kenya, for obtaining ivory.
The surge is part of a nationwide increase in attacks on the animals, according to a report issued earlier this month by the Amboseli Trust for Elephants.
Since the start of 2008, 19 elephants have been killed and another 25 wounded by spears, arrows, and bullets in the Amboseli region near Mount Kilimanjaro, the report added.
Of those killed, ten animals had had their tusks removed, which is the first time in many years that ivory has been taken from Amboseli elephants, the group said.
According to a report in National Geographic News, in the last six weeks, poachers have also killed five elephants in the nearby Tsavo National Park region.
Some were felled by gunfire, others by poisoned arrows.
Conservation groups fear that the rise in poaching is a result of a UN decision to allow the first ivory auction in a decade in 2008, an event that yielded more than a million U.S. dollars from Chinese and Japanese bidders.
"Since the one-off ivory sales from southern Africa countries late last year, we have noted an unprecedented rise of elephant poaching incidents in Tsavo," said Jonathan Kirui, Tsavo National Park's assistant director.
"Our security team is on full alert and is going full force to ensure that the poachers are deterred," he added.
Officials with the Amboseli trust believe poachers are using a poison made from acocanthera shrubs, which are common in Kenya.
"The toxin is frighteningly effective and there is no antidote," the report said.
Poisoning elephants attracts far less attention than shooting them with a gun, wildlife officials note.
"When you shoot an elephant-that loud bang-people will hear it," said Patrick Omondi, head of species conservation at the Kenya Wildlife Service.
"You shoot this elephant with a poisoned arrow, then they follow the elephant until it dies, and then they pluck out the ivory. It's a soft way of killing," he added.